6949830: 6939134 broke Zero

Summary: The commit for 6939134 broke Zero.
Reviewed-by: twisti
Contributed-by: NGary Benson <gbenson@redhat.com>

src/cpu/zero/vm/methodHandles_zero.cpp

@@ -26,6 +26,10 @@
 #include "incls/_precompiled.incl"
 #include "incls/_methodHandles_zero.cpp.incl"
 
+int MethodHandles::adapter_conversion_ops_supported_mask() {
+  ShouldNotCallThis();
+}
+
 void MethodHandles::generate_method_handle_stub(MacroAssembler*          masm,
                                                 MethodHandles::EntryKind ek) {
   ShouldNotCallThis();